Artificial hand



'n', F. ARMSTRONG. ARTIFICIAL HAND.

APPLICATION HLED APR. 13. 1920.

1,37 5,809, Patented; Apr. 26, 1921.

' WITNESSES iii.

v 10- BaberZEfirma'zron'g.

ATTORNEYS v ROBERT FRANCIS ARMSTRONG, OF LA CYGNE, KANSAS.

ARTIFICIAL HAND.

Specification of LettersPa'tent.

Patented Apr. 26, 1921.

Application filed April 13, 1920. Serial No. 373,518.

To all whom "it may concern:

Be it known that I, R-onnn'r FRANCIS ARMSTRONG, a citizen of the United States, and a resident of La Cygne, in the county of Linn. and State of Kansas, have invented certain new and useful Improvements in Artificial Hands, of which the following is a specification.

My invention relates to artificial body members, and more particularly to an improved artificial hand of the type formlng the subject-matter of my Patent No. 1,334,689.

An object of the invention is to provide an improved artificial hand of this character capable of performing all of the important functions of the human hand and in which the movable parts are positively and forcibly actuated and maintained in operative movements and positions respectively, while being easily and readily controlled by the wearer.

Another object is to provide an'improved artificial hand of simple durable construction, reliable in operation and easy and inexpensive to manufacture.

Other objects and advantages reside in certain novel features of construction, arrangement and combination of parts and will become more apparent as the description proceeds, reference being had tothe accompanying drawings forming a part of this specification, and in which:

Figure 1 is a perspective view of my improved hand with the trap-door in the top thereof removed, the'operative parts shown in dotted lines for the sake of illustration;

Fig. 2 is a perspective view of the opera-- tive parts of my invention disassociated from the hand for the sake of illustration;

Fig. 8 is a sectional view through one of the finger members, and

Fig. 4 is a detail view of the thumb joint.

Referring to the drawings, it will be seen that the hand member proper, indicated generally at 5, is of hollow construction, and is preferably constructed of wood and covered with cloth or metal, although any other suitable materials may be employed in the construction. The hand member may be connected to the wrist member (not shown) by any. conventional means. The hand-member proper of course is formed and shaped to approximate the appearance of the human hand.

Rigidly formed with the hand-member proper and curved as shown in the drawings is a middle finger-member, a ring finger member and a little finger member 6, 7 and 8, respectively. These finger members as well as the index finger member and the thumb member to be hereinafter more fully described are preferably constructed as shown in Fig. 8 with a metallic core 9 and a cover 10 therefor.

The index finger member 11 is curved as shown and is provided with an extension 12 which projects into the interior of the hollow hand; The extension is formed with a lateral enlargement 13, which is ap-. ertured to receive a pivot 14: journaled in the hand. This pivot extends substantially perpendicularly to the hand member from the palm to the back thereof and constrains the index finger member to swing toward and away from the middle finger member about an axis extending perpendicularly through the hand member from the palm to the back thereof. 7 y

A bracket consisting of a base 15 secured to the interior wall of the hand member and having its ends bent substantially at right angles to the base and apertured to receive a bearing stud 20, serves to support a coil spring 21 which is mounted upon the bearing stud. The coil spring has its lower arm extended, as at 22, and bearing against the interior wall of the hand member which serves as an abutment therefor. The upper end of the coil spring is extended to form a lateral arm 23 the outer end of which is made to constitute a bearing 24. A. roller 25 having its periphery grooved to ride upon the extension 12 is mounted upon this bearing 24:. It is thus obvious that when the" index finger is operated upon to swing away from the middle finger member such motion 1s resisted by the actlon of the coil spring 21 as this motion sets up tortional stresses in the coil spring tending to reduce its diameter which stresses are of course opposed by the resiliencv of the metal which resists distortion.

An operating cord 26 has an eye 27 secured at its outer end for connection to suitable harness or like means carried by the wearer, and the oppositeend of this cord is connected as at 28, to the extreme outer end of the extension 12. This point of connection is a substantial distance beyond the outermost point of contact of the roller 25 and by thisarrangement the operating cord has a greater leverage with respect to the pivot of said linger member than the spring 21 so that the index finger member may be easily operated. The operating cord 26 extends over guide pulleys 29 and 30, respectively. Theguide pulley 29 is arranged in the forward portion of the hollow hand, and at the opposite end from the point of conneotion so as to be forwardly of this point of connection, as shown. in the drawings. The guide pulley 30 is disposed adj acent to the wrist member, as shown in the drawings.

A thumb member 82 has the inner end of its first phalanx 31 flattened and of general circular form, as indicated at 33, and rotatably mounted in a suitable bearing formed in the hand member by means of a pivot 34 jcurualcd in the hand member and extending through a suitable opening provided in the portion 23 of the thumb member. The motion of the thumb member is thus transverscly of, or approximatelyi transverse to the plane of the palm of the hand and about a pivot substantially parallel with. the pivot 14. The outer phalanx 31 is joined to the inner phala x by a suitable pivot, the phalanges being connected by interfitting tongue and groove structure, shown in detail in Fig. 4. As seen in Fig. 4, the construction of the joint between the inner and outer phalanges is such. that while the outer phalanx may swing freely inwardly it cannot swing outwardly beyond the point where it is alined with the inner phalanx, this being due to the engagement of the portion of the outer phalanx adjacent the joint with the shoulder 36 formed on the outer end of the inner phalanx. The peripheral face of the portion 32 of the inner phalanx is provided with a groove37. A. retractile coil spring 38 has one end secured to the hand member, as at and has its opposite end secured to the thumb member, as at 40, so as to bear against the thumb member in the groove 37. This connection is such that the spring 38 lies in the groove 37 on the inner side of the thumb member, as shown in the draw ings. To the outer side of the thumb member an operating cord 41 is secured, the cord being adapted to bear against the thumb member in the groove 37 on the outer side thereof. The opposite end of the cord is provided with an eye 4'2 which is connected to suitable harness or like means carried by the wearer. It is thus seen. that the coil spring 38 tends to swing the thumb member transversely of the hand, as indicated by the arrows the drawing, and as the outer phalanx of the thumb member 32 normally bears against the index linger member, this action of the coil 38 supplements the action of the spring 21 in maintaining the index finger member against the middle fin er r. L)

member as well as providing a grasping action between the thumb member and the index l'nger member. When the cord 41 is pulled it swings the thumb member away from the index finger member and when so disposed the outer phalanx of the thumb member may be swung inwardly so as to clear the index finger member so that the operating cord 41 is released with the parts in this position, the coil spring 38 will swing the thumb member inwardly against the a 1 of the hand. Such a position of the s is desirable when the hand member is t e used as ahoolr or some lifting capacities or for carrying articles such as a suit case or other baggage or a bucket or like receptacle. When employed for such purposes, it is to be noted that the handle or pi rt of the article grasped is supported by the linger members and is primarily retained in the curved portion of said linger members. If, however, the thumb member is arranged to bear against the index finger member it will serve positively to confinethe handle or like member in position and thereby preclude any possibility of displacement although as before stated when used to per form these or like functions it is usually desirable to have the finger member disposed against the palm of the hand.

It is to be noted that the spring 21 through the extension 12 exerts a relatively powerful leverage on the index finger memer to maintain said index finger member against the middle finger member 6. The arm of the lever through which the spring acts is relatively greater than the arm of the lever to the grlppingportion, the mean point of which portion is indicated by a in the drawings. However,the arm of the lever through which the operating cord 26 acts is considerably greater than the arm of the lever through which the spring 21 acts to provide for easy operation.

The i: dex finger member 11 being forced against the middle finger 12 it will be seen that when the index finger member hasbe'en pulled away from the middle finger member by the operating cord 26 any object such as a pencil, pen or newspaper, the rein of a horse harness or the like may be placed between the index and middle fingers and upon release of the operating cord 26, the spring 21 will force the finger 11 against the finger 6 and effectively grasp the object therein. As shown in Fig. 1 the operating parts are disposed in the hollow hand member which may if desired be provided with a trap door secured in position by a suitable screw or the lilre 44. p

The features of construction, operation and arrangement of parts permit of many or er usages and advantages too numerous mention.

ll claim: 1. An artificial hand comprising a hollow stantially perpendicularly through said hand member from the palm to the back thereof, said index finger member havingan extension projecting into the interior of said handfa bracket arranged in the interior of said hand, a coil spring mounted upon said bracket having one of its ends extended and bearing against the interior wall of said hand member and its other end extended. to form alateral arm havin its outer end constituting a bearing, a roller j ournaled upon said bearing and engaging said index finger member extension whereby the movement of said index finger member away from said middle finger member is resisted by said coil spring, an operating cord connected to the extreme outer end of said extension beyond the outermost point of contact of said roller whereby said operating cord has a greater leverage with respect to said index finger member than said spring, and guide pulleys for said cord member including a pulley j ournaled forwardly of said point of connection, all as and for the purposes set forth.

2. An artificial hand comprising a hollow hand member, a middle finger member rigid with said hand member, an index finger pivotally mounted on said hand member to swing toward and away from said middle finger member on an axis extending substantially perpendicularly through said hand member from the palm in the back thereof, said index finger member having an extension projecting into the interior of said hand, a bracket arranged in the interior of said hand, a coil spring mounted upon said bracket having one of its ends extended and bearing against the interior wall of said hand member and its other end extended to form a lateral arm havin its outer end constituting a bearing, a rol er ournaled upon said bearing and engaging said index finger member extension whereby the movement of said index finger member away from said middle finger member is resisted by said coil spring, and an operating cord connected to the extreme outer end of said extension beyond the outermost point of contact of said roller whereby said operating cord has a greater leverage with respect to said index finger member than said spring.

3. An artificial hand comprising a hollow hand member, a middle finger member rigid with said hand member, an index finger plvotally mounted on said hand member to swing toward and away from said middle finger member on an axis extending substantially perpendicularly through said hand member from the palm to the back thereof,

said index finger member having a projection extending into the interior of said hand, a bracket arranged in the interior of said hand, a coil spring mounted upon said bracket having one of its ends extended and bearing against the interior wall of said hand member and its other end extended to form a lateral arm having its outer end constituting a bearing, a roller journaled upon said bearing and engaging said index finger member extension whereby the movement of said index finger member away from said middle finger member is resisted by said coil spring, a thumb member mounted to swing transversely of said hand having a pivoted end portion adapted to bear against said index finger member, and spring means for urging said thumb member transversely of said hand.

4. An artificial hand comprising a hand member, a middle finger member rigid there with, an index finger member pivotally mounted on said hand to swing toward and away from said middle finger member on an axis extending perpendicularly through said hand member from the palm to the back thereof, spring means connected to said index finger member at a point relatively near said pivot point and urging said index finger against said middle finger, and

means for operating said index finger member connected to the index finger member at a relatively great distance from the pivot point thereon so as to have a greater leverage than said spring means, all as and for the purposes set forth.

5. An artificial hand comprising a hand member, a middle finger member rigid therewith, an index finger member pivotally mounted on said hand to swing toward and away from said middle finger member on an axis extending perpendicularly through said hand member from the palm to the back thereof, said index finger member having an extension, and spring means engaging said extension at a relatively great distance from the pivotal point of said index finger member so as to have a greater leverage with respect to the pivot of said index finger member than the leverage of the force resisting the clasping action, all as and for the purposes set forth.

6. An artificial hand including an end member and a thumb member having the inner end of its inner phalanx pivoted to said end member and provided on its peripheral face with a groove, a retractile coil spring secured at one end to the hand member and at its opposite end to the inner side of the thumb member so as to lie in the peripheral groove, all as and for the purposes set forth.

7 An artificial hand including an end member and a thumb member having the inner end of its inner phalanx pivoted to said end member and provided on its peripheral face with a groove, a retractile coil spring secured at one end to the band member and at its opposite end to the inner side of the thumb member so as to lie in the peripheral groove On said inner side, and an operating cord secured to the outer side of said thumb member and arranged to lie in said peripheral groove on said outer side, all as and for the purposes set forth.

8. An artificial hand comprising a hollow hand member, a middle finger member rigid with said hand member, an index finger pivotally mounted on said hand member to swing toward and away from said middle finger member on an axis extending subby said coil spring. 7

ROBERT FRANCIS ARMSTRONG. 

